1. Field of the Invention
This invention relates to respirator masks. In one of its aspects, the invention relates to respirator masks with a removably mounted corrective lens support frame that is adapted to adjustably mount a corrective lens frame. In another of its aspects, the invention relates to respirator masks with an integral resiliently foldable corrective lens frame. In another of its aspects, the invention relates to respirator masks with a releasable lock to retain a corrective lens frame in adjusted position in the mask. In another of its aspects, the invention relates to respirator masks with a corrective lens support frame that is adapted to mount a corrective lens frame and that is securely retained in the mask.
2. Description of the Related Art
Respirator masks are devices commonly used by military personnel, firefighters, and industrial workers in hazardous environments for protection from inhalation of harmful substances including smoke, chemicals, and biological agents. These respirator masks may employ a filtration system to purify air before it is inhaled by a wearer and thus an air-tight seal between the mask and the wearer's face is crucial during its utilization in a dangerous environment.
Vision correction is necessary for many individuals, including those with an occupation that may require occasional use of a respirator mask, and is a well-known problem in the art. Conventional eye glasses cannot be worn with respirator masks because of lack of space within the mask and the possibility of spectacle side arms jeopardizing the necessarily tight fit of the mask. Contact lenses are an alternate vision correction means, but allergies and other medical conditions may not permit the use of contact lenses for some individuals. Contact lenses are also problematic as these lenses may become polluted with environmental contaminants such as smoke or chemicals, thereby causing problems for the user.
Thus, respirator masks with vision correction lens assemblies to be used by an individual wearing a mask have been developed. Any vision correction assembly must be installed within the mask in order to maintain the air-tight seal needed for the mask to function properly. Since these masks are often used in critical situations, it is also essential that the lenses stay in the correct position during operational use. It is also advantageous to allow for adjustment of the lens position within the mask to accommodate different individuals and also for the assembly to be interchangeable for different prescriptions and removable for those not needing vision correction. It is also desirous for a respirator mask, and subsequently any for any mask insert to be foldable to allow easy handling, transport and retention of fit.
Many such assemblies have been proposed to provide vision correction within a respirator mask, some of which are discussed herein. U.S. Pat. No. 6,019,468 to Altemare, Jr. discloses a spectacle kit having a protective mask insert clip and detachable means for attaching a spectacle front piece firmly to the protective mask insert, by snapping the receiver onto an insert clip. The front piece includes notch attachments for optionally mounting a head strap to the front piece so that the front piece can be worn separately from the mask.
A device for holding spectacles in a mask is disclosed in U.S. Pat. No. 3,563,640 to Wise. The device comprises a spring wire with a wire loop that slidably supports a friction member attached to a spectacles frame. The friction member is vertically adjustable on the wire loop to adjust the vertical position of the spectacles frame. The spring wire is mounted against a window of the mask and is retained in position by spring force thereof.
U.S. Pat. No. 3,004,525 to Nielson discloses a gas mask with an optical insert comprising a nose piece and spectacle frames that are flexible so that the optical insert can be folded onto itself. The optical insert is mounted to the gas mask through a strap having a tip integrally molded to the mask and sized so that the optical insert can be snap fit thereto. The strap forms a loop that can be adjusted to change the position of the optical insert in the gas mask.
A support structure for a protective mask optical insert comprising a pair of hinged eyewires sized to hold corrective lenses is disclosed in U.S. Pat. No. 4,711,539 to Krusas. The eyewires can fold at the hinge onto one another and are biased apart by a pair of torsion springs. The optical insert is mounted to a front hinge block, which is vertically adjustable relative to a back block. An anchor mounted to a structural element located between the face plates of the mask supports the back block and thereby the optical insert inside the face mask.